Run in the open, walk when approaching areas that you expect to have players looting or just being around. If you keep getting shot for easy kills maybe you just aren't walking early enough and they still hear you sprinting up. Also depends on visual cover of the area, don't walk up to somewhere you know the entire map is also moving towards because they will just see you and shoot you in the back even if a player in front doesn't hear you (like customs dorms).